void *doWork(void *args) {
//int id = (long) args;
//printf("Thread %d started.\n", id);
int row = (long) args;
while(row < C->numRows){
//printf("Thread %d multiplying row %d\n", id, row);
multiplyRow(C, A, B, row);
row += numThreads;
}
return NULL;
}
void Tableau::preparePhase1() {
m_slackCount = getInequalityCount();
m_artificialCount = getConstraintCount();
const int constraintCount = getConstraintCount();
int slackIndex = 1;
for(int row = 1; row <= constraintCount; row++) {
for(UINT index = 1; index <= m_slackCount; index++) { // Clear Slack matrix
slackVar(row,index) = 0;
}
for(UINT index = 1; index <= m_artificialCount; index++) { // Clear Artificial matrix
artificalVar(row,index) = 0;
}
artificalVar(row,row) = 1;
Real slackFactor = getSlackFactor(m_table[row].m_relation);
if(slackFactor != 0) { // Set Slack[row,slackIndex]
slackVar(row,slackIndex) = slackFactor;
slackIndex++;
}
if(getRightSide(row) < 0) {
multiplyRow(row,-1);
}
}
// Set temporary object function, with cost factors = 1 for all artificial variables and 0 for the other variables
for(int row = 1; row <= constraintCount; row++) {
int c = m_table[row].m_basisVariable = getArtificialColumn(row);
objectFactor(c) = 1;
}
for(int col = 1; col <= getXCount(); col++) {
objectFactor(col) = 0;
}
for(UINT index = 1; index <= m_slackCount; index++) {
objectFactor(getSlackColumn(index)) = 0;
}
}
/**
* Changes this matrix into its \c ref.
*
* \internal
*
* \return True on success.
*/
bool RMatrix::ref(int startRow) {
int pr, pc;
// row which has elements most left becomes first row
if ((pr = getPivotRow(startRow)) == -1) {
return false;
}
swapRows(startRow, pr);
// where is the pivot element in the 1st row?
if ((pc = getPivotCol(startRow)) == -1) {
return false;
}
multiplyRow(startRow, 1.0 / m[startRow][pc]);
for (int rc = startRow + 1; rc < rows; ++rc) {
addRow(rc, -m[rc][pc], startRow);
}
if (startRow < rows) {
ref(startRow + 1);
}
return true;
}
void Tableau::pivot(size_t pivotRow, size_t pivotColumn, bool primalSimplex) {
TableauRow &row = m_table[pivotRow];
const int leaveBasis = row.m_basisVariable;
const int enterBasis = (int)pivotColumn;
row.m_basisVariable = (int)pivotColumn;
const Real &factor = row.m_a[pivotColumn];
const String enteringVarName = getVariableName(enterBasis);
const String leavingVarName = getVariableName(leaveBasis);
if(isTracing(TRACE_PIVOTING)) {
if(primalSimplex) {
trace(_T("pivot(%2s,%2s). %s -> %s. Cost[%s]:%-15.10lg Tab[%2s,%2s]=%-15.10lg Minimum:%-15.10lg")
,FSZ(pivotRow),FSZ(pivotColumn)
,enteringVarName.cstr(),leavingVarName.cstr()
,enteringVarName.cstr(),getDouble(getObjectFactor(pivotColumn))
,FSZ(pivotRow),FSZ(pivotColumn),getDouble(factor)
,getDouble(getObjectValue()));
} else {
trace(_T("pivot(%2s,%2s). %s -> %s. %s=B[%2s]:%-15.10lg Tab[%2s,%2s]=%-15.10lg Minimum:%-15.10lg")
,FSZ(pivotRow),FSZ(pivotColumn)
,enteringVarName.cstr(),leavingVarName.cstr()
,leavingVarName.cstr(),FSZ(pivotRow),getDouble(getRightSide(pivotRow))
,FSZ(pivotRow),FSZ(pivotColumn),getDouble(factor)
,getDouble(getObjectValue()));
}
}
multiplyRow(pivotRow,1.0/factor);
for(int dstRow = 0; dstRow <= getConstraintCount(); dstRow++) {
if(dstRow != (int)pivotRow) {
addRowsToGetZero(dstRow,pivotRow,pivotColumn);
}
}
}
void Tableau::addConstraint(size_t xIndex, SimplexRelation relation, const Real &rightSide) {
if(xIndex < 1 || (int)xIndex >= getXCount()) {
throwException(_T("addConstraint:Invalid xIndex=%s. Valid interval=[1..%s]"), FSZ(xIndex), FSZ(getXCount()));
}
Real currentValue = 0;
int bvRow = -1;
for(size_t i = 1; i < m_table.size(); i++) {
if(m_table[i].m_basisVariable == (int)xIndex) {
currentValue = getRightSide(i);
bvRow = (int)i;
break;
}
}
String varName = getVariableName(xIndex);
switch(relation) {
case EQUALS :
if(currentValue == rightSide) {
trace(_T("addConstraint:No need to add constraint %s = %-16lg. %s already has the specified value."), varName.cstr(), getDouble(rightSide), varName.cstr());
return;
} else if(currentValue < rightSide) {
relation = GREATERTHAN;
} else {
relation = LESSTHAN;
}
break;
case LESSTHAN :
if(currentValue <= rightSide) {
trace(_T("addConstraint:No need to add constraint %s <= %-16lg. %s=%-16lg."), varName.cstr(), getDouble(rightSide), varName.cstr(), getDouble(currentValue));
return;
}
break;
case GREATERTHAN:
if(currentValue >= rightSide) {
trace(_T("addConstraint:No need to add constraint %s >= %-16lg. %s=%-16lg."), varName.cstr(), getDouble(rightSide), varName.cstr(), getDouble(currentValue));
return;
}
break;
}
if(isTracing(TRACE_ITERATIONS)) {
trace(_T("Add constraint %s %s %lg"), varName.cstr(), getRelationString(relation), getDouble(rightSide));
}
m_table.add(TableauRow(getMaxColumnCount()));
const int newRowIndex = getConstraintCount();
addSlackColumn();
TableauRow &newRow = m_table[newRowIndex];
newRow.m_a[xIndex] = 1;
slackVar(newRowIndex,m_slackCount) = getSlackFactor(relation);
setRightSide(newRowIndex,rightSide);
newRow.m_basisVariable = getSlackColumn(m_slackCount);
objectFactor(newRow.m_basisVariable) = 1;
// if(isTracing()) trace(_T("addConstraint before normalizing:\n %s"),toString().cstr());
if(bvRow >= 0) {
addRowsToGetZero(newRowIndex,bvRow,xIndex);
}
if(getRightSide(newRowIndex) > 0)
multiplyRow(newRowIndex,-1);
// objectValue() += getRightSide(newRowIndex);
}
